This invention relates to a support for a drainage grate of the type comprised of a strip of sheet metal having transverse water drainage slots formed therein. The grates are manufactured in pre-determined lengths and are intended to fit within pre-formed, cast drainage channels. Also disclosed in this application is a support for use with a drainage grate and a process of constructing the slotted drainage grate according to the present invention.
Slotted grates of the general type described in this application are specifically designed to cover relatively narrow drainage channels on or along, for example, roadways or airport runways in order to permit free drainage of water but still provide an uninterrupted relatively level surface free of dangerous depression and holes. In the embodiment shown in this application, the grate is intended to specifically be used as a cover for channels to render the grate safe for use in heavy load/stress environments such as where vehicles will be passing over the grate.
A grating has been marketed under the designation "Aco" which provides the needed additional reinforcement by placing the grate bridge between the slots by means of a second grate. This second grate consists of supports added between the edge tracks which form one unit with the edge tracks. These supports are bent to form a U-shape in the shoulder width corresponding to the division of two slots each. The disadvantage of this type of arrangement is that only every second or third grate bridge can be supported. This is because in order to achieve a certain shoulder width which is greater than the width of the slot flaring, it is necessary to use the material from the width of the adjacent slots. This means that any increases in reinforcement necessitate the use of a heavier guage material.
A further disadvantage occurs in the manufacturing process as the material is bent to form side channels. As it happens, the side tracks cannot provide adequate support to form the edges.